you need to put the sample library into your Sampler Instruments folder
(i think it is Library-Application Support-Logic-Sampler Instruments)
then refresh the ex24 (or close it and open it again). the name of the library should appear and you should be able to browse to the kit you want, then click on it to load into the ex24
I think this should work, but I'm going from memory so my apologies if it doesn't!